Example usage for com.amazonaws.services.dynamodbv2.document.spec ScanSpec ScanSpec

Introduction

In this page you can find the example usage for com.amazonaws.services.dynamodbv2.document.spec ScanSpec ScanSpec.

Prototype

public ScanSpec() 

Source Link

Usage

From source file:com.clicktravel.infrastructure.persistence.aws.dynamodb.DynamoDocumentStoreTemplate.java

License:Apache License

private <T extends Item> ScanSpec generateScanSpec(final AttributeQuery query, final Class<T> tableItemType)
        throws InstantiationException, IllegalAccessException, IllegalArgumentException,
        InvocationTargetException, NoSuchMethodException, SecurityException {
    final Class<?> clazz = getScanSpecOperandType(query.getAttributeName(), tableItemType);

    ScanSpec scanSpec = new ScanSpec();

    final StringBuilder filterExpression = new StringBuilder();
    final ValueMap valueMap = new ValueMap();
    int valueMapCount = 0;

    if (query.getCondition().getComparisonOperator() == Operators.NULL) {
        filterExpression.append("attribute_not_exists(").append(query.getAttributeName()).append(")");
    } else if (query.getCondition().getComparisonOperator() == Operators.NOT_NULL) {
        filterExpression.append("attribute_exists(").append(query.getAttributeName()).append(")");
    } else {//ww w  . java 2 s .c o  m
        if (query.getCondition().getComparisonOperator() == Operators.EQUALS) {
            filterExpression.append(query.getAttributeName()).append(" IN (");

            final Iterator<String> valueIterator = query.getCondition().getValues().iterator();
            while (valueIterator.hasNext()) {
                filterExpression.append(":").append(valueMapCount);
                valueMap.with(":" + valueMapCount, valueIterator.next());
                valueMapCount++;
                if (valueIterator.hasNext()) {
                    filterExpression.append(",");
                }
            }
            filterExpression.append(")");
        } else if (query.getCondition().getComparisonOperator() == Operators.LESS_THAN_OR_EQUALS) {
            if (query.getCondition().getValues().size() == 1) {
                filterExpression.append(query.getAttributeName()).append(" <= ").append(":")
                        .append(valueMapCount);
                final Object valueInstance = clazz.getConstructor(String.class)
                        .newInstance(query.getCondition().getValues().iterator().next());
                valueMap.with(":" + valueMapCount, valueInstance);
                valueMapCount++;
            } else {
                // throw exeption??
            }
        } else if (query.getCondition().getComparisonOperator() == Operators.GREATER_THAN_OR_EQUALS) {
            if (query.getCondition().getValues().size() == 1) {
                filterExpression.append(query.getAttributeName()).append(" >= ").append(":")
                        .append(valueMapCount);
                final Object valueInstance = clazz.getConstructor(String.class)
                        .newInstance(query.getCondition().getValues().iterator().next());
                valueMap.with(":" + valueMapCount, valueInstance);
                valueMapCount++;
            } else {
                // throw exeption??
            }
        }
    }

    if (filterExpression.length() > 0) {
        scanSpec = scanSpec.withFilterExpression(filterExpression.toString());
    }
    if (valueMap.size() > 0) {
        scanSpec = scanSpec.withValueMap(valueMap);
    }
    return scanSpec;
}

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From source file:io.ignitr.dispatchr.manager.core.data.ClientRepository.java

License:Apache License

/**
 * Finds all clients in DynamoDB./*w  ww . j a  va 2s  . co m*/
 *
 * @param offset number of records to offset when paginating
 * @param limit number of records to return when paginating
 * @param sortDir the direction to sort returned records when paginating
 * @param active a boolean flag indicating whether or not to return only "active" clients
 * @return an {@link Observable} that emits all clients
 */
public Observable<Client> findAll(long offset, long limit, String sortDir, boolean active) {
    return Observable.create(subscriber -> {
        Table clientTable = dynamoDB.getTable(CLIENT_TABLE_NAME);

        ItemCollection<ScanOutcome> results = clientTable.scan(new ScanSpec());

        results.forEach(item -> subscriber.onNext(convertFromItem(item)));

        subscriber.onCompleted();
    });
}

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From source file:io.ignitr.dispatchr.manager.core.data.TopicRepository.java

License:Apache License

/**
 * Finds the metadata for all of the topics.
 *
 * @return an {@link Observable} of {@link Topic} containing the metadata about the topic
 *//*  w w w  .  j  a v a2s  .c om*/
public Observable<Topic> findAll() {
    return Observable.create(subscriber -> {
        Table table = dynamoDB.getTable(TOPIC_TABLE_NAME);

        ItemCollection<ScanOutcome> results = table.scan(new ScanSpec());

        results.forEach(item -> {
            Topic metadata = new Topic();
            metadata.setName(item.getString("name"));
            metadata.setArn(item.getString("arn"));
            metadata.setRegistered(true);

            subscriber.onNext(metadata);
        });

        subscriber.onCompleted();
    });
}

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From source file:jp.classmethod.aws.dynamodb.DynamoDbRepository.java

License:Open Source License

@Override
public Chunk<E> findAll(Chunkable chunkable) {
    Preconditions.checkNotNull(chunkable);
    Preconditions.checkArgument(Sort.Direction.DESC != chunkable.getDirection(),
            "DynamoDB only supports scanning forwards");
    ScanSpec spec = new ScanSpec();
    if (false == Strings.isNullOrEmpty(chunkable.getPaginationToken())) {
        spec.withExclusiveStartKey(new PrimaryKey(hashKeyName, chunkable.getPaginationToken()));
    }/*from  w  ww . jav  a 2 s .c  o m*/
    spec.withMaxPageSize(chunkable.getMaxPageSize()).withMaxResultSize(chunkable.getMaxPageSize());

    final ItemCollection<ScanOutcome> results = table.scan(spec);

    final List<Item> itemList;
    try {
        itemList = Lists.newArrayList(results.iterator());
    } catch (AmazonClientException e) {
        throw convertDynamoDBException(e, "scan", null /* conditionMessage */);
    }
    final List<E> entities = itemList.stream().map(this::convertItemToDomain) //O(n)
            .collect(Collectors.toList()); //O(n)
    final Map<String, AttributeValue> lastEvaluatedKey = results.getLastLowLevelResult() == null ? null
            : results.getLastLowLevelResult().getScanResult().getLastEvaluatedKey();
    final String paginationToken = lastEvaluatedKey == null ? null : lastEvaluatedKey.get(hashKeyName).getS();
    return new ChunkImpl<>(entities, paginationToken, chunkable);
}

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From source file:vfma.LoadSensorData.java

License:Open Source License

public ArrayList<RawSensorData> getSensorData(String lastTimestamp) throws VFMException {

    ArrayList<RawSensorData> rsdlist = new ArrayList<RawSensorData>();

    try {//from   w  w w.ja  v  a2 s.  co m

        AmazonDynamoDBClient client = new AmazonDynamoDBClient()
                .withEndpoint("https://dynamodb.us-west-2.amazonaws.com");
        DynamoDB dynamoDB = new DynamoDB(client);
        Table table = dynamoDB.getTable("sensorData");
        ScanSpec scanSpec = new ScanSpec();

        System.out.println("Get sensors...");
        ItemCollection<ScanOutcome> items = table.scan(scanSpec);

        String lastTimeValue;

        Iterator<Item> iter = items.iterator();
        while (iter.hasNext()) {
            Item item = iter.next();

            RawSensorData rsd = new RawSensorData();

            rsd.setTimestamp(item.getJSON("pass").replace("\"", ""));
            final JSONObject rawData = new JSONObject(item.getJSON("payload"));
            rsd.setSensorId(rawData.getString("sensor_id_time"));
            rsd.setPassing(rawData.getString("passing"));

            System.out.println("Read " + rsd.getSensorId());

            if (rsd.getTimestamp().compareTo(lastTimestamp) > 0)
                rsdlist.add(rsd);

            lastTimeValue = rsd.getTimestamp();
        }

    } catch (Exception e) {
        System.err.println("Unable to scan the table:");
        System.err.println(e.getMessage());
    }

    return rsdlist;
}

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